// SPDX-License-Identifier: MIT
// SPDX-FileCopyrightText: Copyright © 2005-2020 Rich Felker, et al.

#ifndef _LIBM_H
#define _LIBM_H

#include <stdint.h>
#include <float.h>
#include <math.h>

#define hidden

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
union ldshape {
  long double f;
  struct {
    uint64_t m;
    uint16_t se;
  } i;
};
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __BIG_ENDIAN
/* This is the m68k variant of 80-bit long double, and this definition only works
 * on archs where the alignment requirement of uint64_t is <= 4. */
union ldshape {
  long double f;
  struct {
    uint16_t se;
    uint16_t pad;
    uint64_t m;
  } i;
};
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
union ldshape {
  long double f;
  struct {
    uint64_t lo;
    uint32_t mid;
    uint16_t top;
    uint16_t se;
  } i;
  struct {
    uint64_t lo;
    uint64_t hi;
  } i2;
};
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __BIG_ENDIAN
union ldshape {
  long double f;
  struct {
    uint16_t se;
    uint16_t top;
    uint32_t mid;
    uint64_t lo;
  } i;
  struct {
    uint64_t hi;
    uint64_t lo;
  } i2;
};
#else
#error Unsupported long double representation
#endif

/* Support non-nearest rounding mode.  */
#define WANT_ROUNDING 1
/* Support signaling NaNs.  */
#define WANT_SNAN 0

#if WANT_SNAN
#error SNaN is unsupported
#else
#define issignalingf_inline(x) 0
#define issignaling_inline(x) 0
#endif

#ifndef TOINT_INTRINSICS
#define TOINT_INTRINSICS 0
#endif

#if TOINT_INTRINSICS
/* Round x to nearest int in all rounding modes, ties have to be rounded
   consistently with converttoint so the results match.  If the result
   would be outside of [-2^31, 2^31-1] then the semantics is unspecified.  */
static double_t roundtoint(double_t);

/* Convert x to nearest int in all rounding modes, ties have to be rounded
   consistently with roundtoint.  If the result is not representible in an
   int32_t then the semantics is unspecified.  */
static int32_t converttoint(double_t);
#endif

/* Helps static branch prediction so hot path can be better optimized.  */
#ifdef __GNUC__
#define predict_true(x) __builtin_expect(!!(x), 1)
#define predict_false(x) __builtin_expect(x, 0)
#else
#define predict_true(x) (x)
#define predict_false(x) (x)
#endif

/* Evaluate an expression as the specified type. With standard excess
   precision handling a type cast or assignment is enough (with
   -ffloat-store an assignment is required, in old compilers argument
   passing and return statement may not drop excess precision).  */

static inline float eval_as_float(float x) {
  float y = x;
  return y;
}

static inline double eval_as_double(double x) {
  double y = x;
  return y;
}

/* fp_barrier returns its input, but limits code transformations
   as if it had a side-effect (e.g. observable io) and returned
   an arbitrary value.  */

#ifndef fp_barrierf
#define fp_barrierf fp_barrierf
static inline float fp_barrierf(float x) {
  volatile float y = x;
  return y;
}
#endif

#ifndef fp_barrier
#define fp_barrier fp_barrier
static inline double fp_barrier(double x) {
  volatile double y = x;
  return y;
}
#endif

#ifndef fp_barrierl
#define fp_barrierl fp_barrierl
static inline long double fp_barrierl(long double x) {
  volatile long double y = x;
  return y;
}
#endif

/* fp_force_eval ensures that the input value is computed when that's
   otherwise unused.  To prevent the constant folding of the input
   expression, an additional fp_barrier may be needed or a compilation
   mode that does so (e.g. -frounding-math in gcc). Then it can be
   used to evaluate an expression for its fenv side-effects only.   */

#ifndef fp_force_evalf
#define fp_force_evalf fp_force_evalf
static inline void fp_force_evalf(float x) {
  volatile float y;
  y = x;
}
#endif

#ifndef fp_force_eval
#define fp_force_eval fp_force_eval
static inline void fp_force_eval(double x) {
  volatile double y;
  y = x;
}
#endif

#ifndef fp_force_evall
#define fp_force_evall fp_force_evall
static inline void fp_force_evall(long double x) {
  volatile long double y;
  y = x;
}
#endif

#define FORCE_EVAL(x)                         \
  do {                                        \
    if (sizeof(x) == sizeof(float)) {         \
      fp_force_evalf(x);                      \
    } else if (sizeof(x) == sizeof(double)) { \
      fp_force_eval(x);                       \
    } else {                                  \
      fp_force_evall(x);                      \
    }                                         \
  } while (0)

#define asuint(f) \
  ((union {       \
    float _f;     \
    uint32_t _i;  \
  }) {f})         \
    ._i
#define asfloat(i) \
  ((union {        \
    uint32_t _i;   \
    float _f;      \
  }) {i})          \
    ._f
#define asuint64(f) \
  ((union {         \
    double _f;      \
    uint64_t _i;    \
  }) {f})           \
    ._i
#define asdouble(i) \
  ((union {         \
    uint64_t _i;    \
    double _f;      \
  }) {i})           \
    ._f

#define EXTRACT_WORDS(hi, lo, d) \
  do {                           \
    uint64_t __u = asuint64(d);  \
    (hi) = __u >> 32;            \
    (lo) = (uint32_t)__u;        \
  } while (0)

#define GET_HIGH_WORD(hi, d)  \
  do {                        \
    (hi) = asuint64(d) >> 32; \
  } while (0)

#define GET_LOW_WORD(lo, d)       \
  do {                            \
    (lo) = (uint32_t)asuint64(d); \
  } while (0)

#define INSERT_WORDS(d, hi, lo)                              \
  do {                                                       \
    (d) = asdouble(((uint64_t)(hi) << 32) | (uint32_t)(lo)); \
  } while (0)

#define SET_HIGH_WORD(d, hi) INSERT_WORDS(d, hi, (uint32_t)asuint64(d))

#define SET_LOW_WORD(d, lo) INSERT_WORDS(d, asuint64(d) >> 32, lo)

#define GET_FLOAT_WORD(w, d) \
  do {                       \
    (w) = asuint(d);         \
  } while (0)

#define SET_FLOAT_WORD(d, w) \
  do {                       \
    (d) = asfloat(w);        \
  } while (0)

hidden int __rem_pio2_large(double*, double*, int, int, int);

hidden int __rem_pio2(double, double*);
hidden double __sin(double, double, int);
hidden double __cos(double, double);
hidden double __tan(double, double, int);
hidden double __expo2(double, double);

hidden int __rem_pio2f(float, double*);
hidden float __sindf(double);
hidden float __cosdf(double);
hidden float __tandf(double, int);
hidden float __expo2f(float, float);

hidden int __rem_pio2l(long double, long double*);
hidden long double __sinl(long double, long double, int);
hidden long double __cosl(long double, long double);
hidden long double __tanl(long double, long double, int);

hidden long double __polevll(long double, const long double*, int);
hidden long double __p1evll(long double, const long double*, int);

extern int __signgam;
hidden double __lgamma_r(double, int*);
hidden float __lgammaf_r(float, int*);

/* error handling functions */
hidden float __math_xflowf(uint32_t, float);
hidden float __math_uflowf(uint32_t);
hidden float __math_oflowf(uint32_t);
hidden float __math_divzerof(uint32_t);
hidden float __math_invalidf(float);
hidden double __math_xflow(uint32_t, double);
hidden double __math_uflow(uint32_t);
hidden double __math_oflow(uint32_t);
hidden double __math_divzero(uint32_t);
hidden double __math_invalid(double);
#if LDBL_MANT_DIG != DBL_MANT_DIG
hidden long double __math_invalidl(long double);
#endif

#endif
